Apparatus for feeding pen-driving current

ABSTRACT

An apparatus for feeding pen-driving current through a feeding wire to movable pen means including a wire winding drum rotatably journaled to a fixed member, the feeding wire being wound around the drum, and resilient means urging the drum to turn in the winding direction of the wire.

United States Patent 51 3,683, 11 1 Ikeda Aug. 8, 1972 54] APPARATUS FORFEEDING PEN- [56] References Cited DRIVING CURRENT UNITED STATES PATENTS[72] Inventor: Tetsusaburo Ikeda, Tokyo, Japan 2,751,565 6/1956 Johnson..339/5 RL [731 Elem 3,351,949 H1967 Brown ..346/l4l x Japan [22] Filed:Aug. 17, 1970 Primary Examiner-Joseph W. Hartary pp No: 64,406Attorney-McDougall, Hersh & Scott [57] ABSTRACT P D t [30] Foreign App[Canon y a a An apparatus for feeding pen-driving current through Aug.25, 1969 Japan ..44/79898 a feeding wire to movable pen means includinga wire winding drum rotatably journaled to a fixed member, 346/139 3,339/5 RL the feeding wire being wound around the drum, and [51] Int. Cl...G0ld 15/24 resilient means urging the drum to turn in the winding [58]Field of Search ......346/l39, 141, 29; 339/5 RL,

direction of the wire.

1 Claim, 5 Drawing Figures PATENTEDA B 1 12 3.683.411

SHEEI 2 OF 3 FIG. 2

PATENTEUAUG 8 1922 3.683 '41 1 sum 3 or 3 APPARATUS FOR FEEDINGPEN-DRIVING CURRENT FIELD OF THE INVENTION This invention relates to an.apparatus for feeding pen-driving current generally and, moreespecially, to an apparatus that feeds pen-driving current travellingcontinuously or intermittently through a feeding wire to pen means asseen in an X-Y recorder or similar apparatus.

The X-Y recorder or similar apparatus has pen means on a Y axisdirection travel stand or pen stand. The pen-driving current or signalthat moves the pen up and down against a construction surface hasconventionally been supplied to the pen means from the signal source orcontrol switch by means of the following methods. In one of thesemethods, current feeding is done directly by the feeding wire insuspension. In this method, however, the suspended feeding wire and itsattachments get in the way when replacing the construction surface andchecking-up in the course of construction. In another instance of thesaid methods, the guide portion (it travels jointly with X axisdirection travel stand and consists, for example, of guide rails orrods) of the pen stand is provided with a slender feeding wire or afeeding plate extending along the travel direction of the pen stand andthe feeding element on the pen stand while contacting with feeding wireor feeding plate is arranged to travel jointly with the said pen stand.This method, however, renders poor contact due to presence of dust andfriction at the contacting portion between the feeding wire or feedingplate and the feeding element. In another instance of the said methods,current feeding is done using traction wire for moving the pen stand tothe Y axis direction as the feeding wire. In this method, however, itcontacts with the signal source is achieved by sliding contact at theend portion of the signal source of the said wire. And, as such, in thismethod, too, contact is poor due to presence of dust and friction and,therefore, maintenance and check-ups are constantly needed.

SUMMARY AND OBJECT OF THE INVENTION Accordingly, an object of thisinvention is to provide an apparatus for feeding pen-driving currentwhich assures constant feed of the driving current or signal from signalsource or control switch to pen means.

Another object of this invention is to provide an apparatus for feedingpen-driving current in which the presence of feeding wire causes littleor no inconvenience when replacing the construction surface orchecking-up in the course of construction.

According to the present invention, an apparatus for feeding pen drivingcurrent provides a feeding wire winding drum rotatably journaled at afixing member that relatively travels against the pen means. This drumis wound from several to odd times, for example about four times, byfeeding wire, such as, flator sectionally round-shaped coated wire orcable. The drum is resiliently urged in the winding direction of thefeeding wire by resilient means, such as, a spiral spring and othersprings.

The above and the other objects, features and advantages of thisinvention will become apparent from the following detailed descriptionof the illustrated embodiment in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a partial perspectiveview of one embodiment of an X-Y recorder in which an apparatus forfeeding the pen-driving current in accordance with this invention isset;

FIG. 2 represents a longitudinal cross-sectional view of the apparatusfor feeding the pen-driving current shown in FIG. 1;

FIG. 3 is a perspective view of the overhauled inner portion of theapparatus for feeding the pen-driving current shown in FIGS. 1 and 2;

FIG. 4 shows a longitudinal cross-sectional view of the overhauled outerportion of the apparatus for feeding the pen-driving current shown inFIGS. 1 and 2; and

FIG. 5 illustrates a perspective view, in the apparatus for feeding thepen-driving current shown in FIGS. 1-4, of the upper element of cablewinding drum, upside down, devoid of majority of cable, showing how apair of flat cables are connected to each other.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT In FIG. 1, an X-Yrecorder 10 has at its left and right of side guide rails 14 of H typecross section supported on the fixed stand 12 (In FIG. 1, one only ofthe rail pairs 14 is shown). On these rails 14, trucks 16 travel in theX axis direction in the direction of arrow X as seen in FIG. 1 (In FIG.1, only one of the trucks 16 is shown).

Fitting of these is done in the following way. Firstly, a pair of guidewheels 18 and 20 rotatably journaled in the front and rear ends of thetrucks 16 are rotatably put on the guide rails 14. Next a pair of guidewheels 22 and 24 rotatably journaled near the front and rear ends of theinside of the back of the trucks 16 are put in guide grooves 26 of theinside of guide rails 14 so as to rotate in one side of the rails 14.Then a pair of guide wheels (none of these is shown in the drawing)rotatably journaled near the front and rear ends of the outside of theback of the trucks 16 are put in the guide grooves 28 of the outside ofthe guide rails 14 so as to rotate in the other side of the rails 14.

On each of these trucks 16 is fixed an L-shaped plate 30 respectively.Between these plates are bridged a pair of guide rods 32 and 34respectively. These guide rods 32 and 34 are fitted with a Y axisdirection travel stand or pen stand 36 to enable moving to the directionof Y axis, i.e. the direction of an arrow Y in FIG. 1. On the pen stand36 are plural numbered, for example 4, electromagnetic pen means 38, 40,42 and 44 respectively.

Further, in FIG. 1, driving means for driving trucks 16 to travel in thedirection of the X axis and stand 36 to travel to the direction of Yaxis respectively is not shown. Various conventional driving means maybe employed for this purpose.

In the X axis direction travel truck 16 is fitted with apparatus 50 forfeeding the pen-driving current in a state of suspension. This fittingis done by fixing the fixed axis 56 of the feeding apparatus 50 on theL- shaped suspension plate 52 screwed to fitting plate 30 by means ofscrew 54. The inner end 134A of the winding portion 134 of flat cable 60extending downward from an opening 58 at the end of fixed axis 56 isfixed on the base plate 17 of truck 16. On this base plate 17, one end66A of another flat cable 66 is affixed by means of fixture 64. Cores ina plural number, for example 5 lines, exposed at the end of cable 66 areconnected by soldering with a plural number, for example five lines, ofcores 68 exposed at the end 134A of the flat cable 60 respectively.

The other end 66C of flat cable 66 is affixed on the back of fixed stand12 by fixture 70 to give a sag similar to sag 66B whose length is equalto about one half of the travel limit in the direction of X axis of thetruck 16. As the fixing is done at about the center portion of the frontand rear direction (similar to the direction of X axis) of the fixedstand 12, if the sag 66B is equal to about a half of the travel limit ofX axis direction of the truck 16, the truck 16 can travel up to themaximum travel limit. It is possible to remove the sag 66B by addinganother feeding apparatus 50 as may be detailed later. As, however, thesag 66B doesnt hinder the travel of truck 16 to any extent, the removalof sag is not necessary. In FIG. 1, for the sake of showing it clearly,the position of fixture 70 is shown a bit forward from the actualposition. At the other end 66C of flat cable 66 the cores 68 arerespectively connected with the prescribed signal source or controlswitch (neither of them are shown in the drawing). The outer end 136B ofwinding portion 136 of flat cable 74 extending outward from thecircumference of hub portion 104 of cable winding drum 102 of thefeeding apparatus 50 is fixed on a side of the pen stand 36 by fixture76. One end 74A of said cable .74 extends from the lower side of the penstand 36 upwards through an opening (not shown in the drawing) passingthrough upward and downward'of the pen stand 36. Plural numbered cores68, for example five lines, exposed at end 74A are connected with inputterminals of electromagnetic pen means 38, 40, 42 and 44 respectivelyvia terminal boxes 78, 80, 82 and 84. Four out of five cores are plusterminals corresponding to four electromagnetic pen means while theremaining one core represents minus terminal commonly applied to fourelectromagnetic pens.

Particulars of the feeding apparatus 50 are shown in FIGS. 2 and 4. Onthe upper end of upper small radius portion 57 of the fixed axis offeeding apparatus 50 a slender projection portion 86 is formed. Thisprojecting portion 86 is put in an opening 88 being almost similar tosaid portion 86 and formed in the suspension plate 52 whereby the fixedaxis 56 is held against rotation relative to suspension plate 52. Theprojecting portion 86 has a tapped hole 89. Into this hole, screw 54 isscrewed through suspension plate 52, washer 90 and spring washer 92whereby fixed axis 56 is fixed on the suspension plate 52.

Around the center of the fixed axis 56 is formed a large radius portion94. The fixed axis 56 has a center hole 96 which has an opening 58 atthe lower end of lower small radius portion 59 of this axis with itsupper end being blocked up. On a large radius portion 94 is formed aslit 98 extending in a longitudinal direction of the fixed axis 56. Theslit 98 extends from the center hole 96 to the outer circumference oflarge radius portion 94.

On the outer circumference of upper small radius portion 57 of the fixedaxis 56 are formed a ring-shaped groove 100 and slit 101 extending inthe axial direction.

The cable winding drum 102 is provided with an upper element 108consisting of a cylindrical hub portion 104 and a disk-shaped flangeportion 106 making a unit with the hub portion at its upper end. On thelower end of the hub portion 104 of this element 108 are formedprojected portions 110, 112, 114 and 116 respectively arranged at adistance of about 90 degrees. These projecting portions are forcibly putin to openings 120, 122, 124 and 126 respectively that correspond with adisk-shaped lower element 118 of drum 102 thereby are fitted in a mannerthat the lower element 118 produces a lower flange portion of drum 102at the lower end of hub portion 104.

Into the center hole 130 formed at the flange portion 106 of upperelement 108 the upper small radius portion 57 of fixed axis 56penetrates rotatably. Between the lower surface of flange portion 106and the upper surface of large radius portion 94 of axis 56 is washer132 that penetrates into small radius portion 57.

To the inner space 128 of drum 102 that is formed by hub portion 104, apair of flange portions 106 and 118 and large radius portion 94 of axis56, the loosely wound and ring-shaped winding portion 134 of flat cable60 is put in before the flange portion 118 is fitted on the hub portion104. The inner end 134A of said winding portion extends downward of thefixed axis 56 from the lower-end opening 58 through slit 98 and centerhole 96.

On the circumference of hub portion 104 is a winding portion 136 of flatcable 74 which is a bit tightly wound and ring-shaped. 5 cores 68exposing to the outer end 134B of winding portion 134 and 5 cores 68exposing to the inner end 136A of winding portion 136 are connectedrespectively.

The connection is done in this way: Firstly, a part of outer end 1348combines with the inner circumference of hub portion 104 by means ofadhesives layer 140 at around slit 138 formed in the hub portion 104likely extending to the direction of axis center through the projectedportion 76. Next, a part of the inner end 136A combines with the outercircumference of hub portion 104 by means of adhesives layer 142 ataround slit 138. Next, the cores 68 exposing respectively to said ends134B and 136A get contacted with other via slit 138. Then, these contactportions are connected with respective cores 68 after being soldered.

In this state, as already described, the lower element 1 18 is rotatablyattached to the small radius portion 59 of fixed axis 56 and isconnected with the upper element 108. Then, a bushing 144 is attached tothe lower small radius portion 59 of axis 56 and the small radiusportion 146 having portions 146A and 14613 is put in the center hole 148of lower element 118. Next, a washer 150 is put in the small radiusportion 59 of axis 56 and, further, a screw portion formed on thecircumference of this small radius portion is screwed jointly with nut152.

The upper small radius portion 57 of fixed axis 56 is penetrated by aspiral spring 154. The inner end 154A of said spiral spring is put insaid slit 101 of axis 56 whereby its end is affixed on the axis 56. Onthe surface of upper flange portion 106 of drum 102, a cup-like springbox 156, into the center hole 157 of which the upper small radiusportion 57 of axis 56 is relatively rotatably penetrated, is fitted in astate of holding a spiral spring 154 in said box. This fitting is donein this way, i.e. the projecting portions 158, 160, 162 and 164 that arepositioned at nearly the same interval at the lower end of the box areforcibly put into the respective openings 166, 168, 170 and 172 formedon the flange portion 106. The outer end 154B of spiral spring 154 isput in the slit 174 formed to extend to the axial direction along thecircumference of spring box 156 whereby the outer end 1548 is affixed onthe spring box 156. As the spring 154 is urged resiliently in thewinding direction in itself under its fitting condition, the spring box156 jointly with drum 102 that makes a unit is urged resiliently to pulland wind in the direction marked by arrow A in FIG. 1 the outer end 1368of winding portion 136 of wire 74.

On the surface of spring box 156 is a washer 176 attached to the smallradius portion 57 of axis 56. On the upper side of the washer is aU-shaped stop ring 178. By strongly screwing down nut 152, therefore, itis possible to eliminate an axial direction play of spring box 156 andcable winding drum 102.

Therefore, when put in use, as practiced in the prior art, the X axisdirection travel truck 16 can travel in the X axis direction againstguide rail 14 and the pen stand 36 to the Y axis direction against guiderods 32 and 34 respectively by driving means, whereby the pen stand 36can travel to any optional position in either direction of X axis or Yaxis against a construction (not shown) on the fixed stand 12. Then, aprescribed signal is respectively given to electromagnetic pen means 38,40, 42 and 44 from the prescribed signal source or control switchthrough the respective cores of flat cables 66, 60 and 74 whereby aprescribed drawing on said construction is done by dropping selectivelythe respective pens of pen means 38, 40, 42 and 44 for necessaryconstruction.

When the X axis direction travel truck 16 travels, the extent of sag 66Bof flat cable 66 increases or decreases in accordance with the travelposition of truck 16.

However, the sag 66B disappears substantially as the travel distancereaches a maximum. Hence it will cause no hinderance to the travel oftruck 16.

On the other hand, when the Y axis direction travel stand or pen stand36 travels, for example when it travels from right to left in FIG. 1,the flat cable 74 will tend to sag. But the spring box 156 and the cablewinding drum 102 that make a unit are resiliently urged,

because of spiral spring 154, in a manner that the outer end 136B ofwinding portion 136 of flat cable 74 is wound on the winding portion136. Thereby, when said sag of cable 74 is about to get caused, the drum102 rotates in the direction of winding cable 74. Thereby, said sag isabsorbed by winding of outer end 1363 to the winding portion 136.Thereby, no sag will be caused on the flat cable 74. Contrary to theabove assumption, when the pen stand 36 travels from left to right inFIG. 1, the spiral spring 154 gets rewound overcoming the elastic strainforce or spring force of said spring and the spring box 156 and cablewinding drum 102 respectively rotate. As the winding portion 136 ofcable 74 and its outer end 13613 are rewound, said travel of pen stand74 is carried out smoothly. As said rewinding amount of winding portion136 corresponds to the distance of travel of pen stand 74, cable 74 willcause no sag between the feeding apparatus 50 and fixture 76.

When the winding portion 136 of cable 74 is wound or rewound by drum102, the drum 102 rotates. This rotation is transmitted to the outer end1348 of winding portion 134 of flat cable 60 and, for this reason, theouter end also rotates. As the winding portion 134 is loosely wound,said rotation, for example several rotations, will not be transmitted upto the inner end 134A of winding portion 134 as the rotation is absorbedbetween the outer end 1348 and inner end 134A. Thereby, the inner end134A of winding portion 134 will never be twisted. The inner end, alwaysin a predetermined state, extends downward from an opening 148 at thelower end of drum 102.

When the pen stand 36 travels from the nearest position of the feedingapparatus to the fartherest, the frequency of drum rotation can bechanged from a few to ten odd times, for example abut four times. By theuse of spiral spring 154 having an appropriate spring constant, thetorque given to drum 102 via spring 154 can be regulated on a fixedstandard, for example about 100 about 150 g/cm. in this case, the outerdiameter of hub portion 104 of drum 102 ranges between about 30 90 mm,for example about mm.

Further, flat cables 60, 66 and 74 can be those made by solid orstranded wire placed in side by side relationship with several wiresbeing nearly parallel with each other and coated by synthetic resin. Bythe use of this kind of cable it is possible to supply pen-drivingsignals, from several circuits.

When silicon oil is put on the respective surface of flat cables 60, 66and 74, friction on these surfaces will be minimized and smoothfunctioning of said feeding apparatus 50 may be ensured.

Although the illustrative embodiment of this invention has beendescribed in detail above with reference to the accompanying drawings,it is to be understood that this invention is not limited to thisprecise embodiment, and that various changes and modifications may beeffected therein by one skilld in art without departing from the scopeor spirit of the invention.

What is claimed is:

1. An apparatus for feeding pen-driving current comprising a feedingmember and pen means traveling relative thereto, a cable-winding drumrotatably attached to said member, current feeding wire, resilient meansnormally urging said drum in one direction of rotation for winding saidcurrent-feeding wire about the outer circumference of the drum, saiddrum being rotatably 50 joumaled on a fixed axis to said feeding memberand wherein said resilient means comprises a spiral spring associatingits inner end with said axis and, concurrently, its outer end with saiddrum, said feeding wire comprising a winding portion and outer and innerend portions, means electrically connecting the outer end of saidwinding portion to said pen means and means electrically connecting theinner end of said winding portion to a signal source or controloperating to unwind or rewind current feeding wire in relation to thetravel direction and distance of said pen means relative to said feedingmeans, said resilient means operating to avoid any sag in said windingportion between said drum and said pen means, and wherein said feedingwire is provided with a second winding portion wound loosely between theouter circumference of said fixed axis and the inner circumference ofsaid drum, the outer end of said second winding portion beingelectrically connected with the inner end of said first winding portion,and the inner end of said second winding portion stretching outsidethrough a center hole defined by said fixed axis whereby said feedingwire can avoid twisting when said drum rotates, said inner end of saidsecond winding portion extending to said signal source or control.

1. An apparatus for feeding pen-driving current comprising a feedingmember and pen means traveling relative thereto, a cablewinding drumrotatably attached to said member, current feeding wire, resilient meansnormally urging said drum in one direction of rotation for winding saidcurrent-Feeding wire about the outer circumference of the drum, saiddrum being rotatably journaled on a fixed axis to said feeding memberand wherein said resilient means comprises a spiral spring associatingits inner end with said axis and, concurrently, its outer end with saiddrum, said feeding wire comprising a winding portion and outer and innerend portions, means electrically connecting the outer end of saidwinding portion to said pen means and means electrically connecting theinner end of said winding portion to a signal source or controloperating to unwind or rewind current feeding wire in relation to thetravel direction and distance of said pen means relative to said feedingmeans, said resilient means operating to avoid any sag in said windingportion between said drum and said pen means, and wherein said feedingwire is provided with a second winding portion wound loosely between theouter circumference of said fixed axis and the inner circumference ofsaid drum, the outer end of said second winding portion beingelectrically connected with the inner end of said first winding portion,and the inner end of said second winding portion stretching outsidethrough a center hole defined by said fixed axis whereby said feedingwire can avoid twisting when said drum rotates, said inner end of saidsecond winding portion extending to said signal source or control.